Jack-arm for excavating-machines.



PATENTED AUG. 22, 21.905.,

E. B. STONE.

JACK ARM FOR BXCVATING MACHINES.

APPLICATION ILED JULY 6. 1904.

UNITED STATES PATENT OFFICE.

EGBERT B. S"ONE, OF OAKLAND, CALIFORNIA, ASSIGNOR TO E. B. & A. L. STONE COMPANY, OF OAKLAND, CALIFORNIA, A CORPORATION OF CALIFORNIA.

JACK-AFIN! FOR EXCAVATlNG-MACHINES.

Speeicaten of Letters Patent.

Patented Aug. 22, 1905.

Application filed July 6, 1904:. Serial No. 215,467.

Beit known that I, EGBERT B. STONE, a citizen of the United States, residing at Oakland, county of Alameda, State of California, .have invented certain new and useful Improvements in Jack-Arms for Fxeavating- Machines; and I do hereby declare the following to be a full, clear, and exact description of the same. y

The present invention relates to certain new and useful means for preventing the upsetting, lateral tilting, or derailing of an excavating apparatus by reason of the lateral strain placed thereon during the operation of the excavating bucket or scoop at a dis tance from the apparatus, thereby permitting the use of a boom of materially greater length than those at present in use, and the consequent utilization in the excavating of" a much wider cut, trench, canal, or cut than possible with the scoop or bucket excavating apparatus in general use for the removal of earth in connection with contract work gen orally.

To comprehend the invention, reference should be had to the accompanying sheet oi drawings, wherein- Figure I is an end view disclosing an ordinary dirt-excavating machine within the line ot cut, the jack-arms being illustrated in adjusted position. Fig. 2 is a detail sectional end View of one ofi the ear-plates to which the upper end of the jack-arm is held, the jackarm being broken away. Fig. 3 is a broken detail view of the lower end of one of the jackarms, the socketplate, and the shoe or footplate of the jack being sectioned Fig. l is a liront view of the devices disclosed by Fig. 2 of the drawings, and Fig. 5 is a top plan view of one of the shoe or toot-plates.

The .numeral I is used te designate the body or carriage of an ordinary excavating apparatus or car, which is mounted upon suitable wheels designed to work en tracks arrai'iged Within the line of cut or excavation. On this car is mounted a supporting A-standard 2, to the upper end ol which is secured any suitable head 3. In the present case there are connected to the head 3 by a transverse bolt 7 the ear-plates 4, from which plates project the ears 4. Between these ears is hinged the upper end of the jack-arms 5, which arms in the present case are held between the ears 4 by means of the bolts 6.

To the lower end of each jack-arm is secured a socket-plate 8, into which screws the jack 9. This jack is adjustable within the socket-plate and has connected thereto the shoe or foot-plate l0, the free end of the jack 9 fitting within the socket-opening 10 of the shoe or plate l0. By this manner of connecting the jack and the shoe or Jfoot-plate 10 the said shoe or foot-plate 10 is permitted such movement as will permit of the same being swung at an angle to the jack-arm 5. As is usual with this class of machinery the boom ll is connected at one end to the carriage or car l from said boom being suspended the scoop or excavatingbucket 12. The dipper-handle 13 ofthe scoop or excavatingbucket works over a supporting-roll secured to the boom Il, said boom being held at an inclination by means of the tie-rod 14, which forms connection between the boom and the head 3 et the A-standard 2. The scoop or excavating-bucket 12 is raised and lowered by means of the cable or chain 15.

By the employment of the described jackarm which swings `from the head of the An standard the use of a much longer boom is permitted than is capable of use under the present constructed bucket excavating apparatus.` Hence the machine maybe utilized for the forming of a much wider cut or the delivery of the dirt or material at a greater distance from the machine.

Inasmuch as the angle or inclination of the jackarms may be readily varied or changed and the length increased or de creased by screwing the jack Q inward. or outward, the same are capable el adjustment in accordance with the width of the cut to be excavated. Owing to the extended area covered, by the jack-arms 5, it is anilnpossibility to upset the machine proper by reason of lateral pressure placed or brought to bear thereon by the weight due to the strain el the scoop or bucket 12 while being 'filled It is obvious that a greater resistance is ol'lered to the lateral strain brought onto the apparatus where the aek-arms are hinged to the upper structure of the machine 1 than where the jack means lead from the base thereof and that as a consequence a longer boom may be utilized, Which results in the apparatus being capable of successful use in the excavating of a much Wider cut. riChe shoe or foot-plate 10 When the jack-arms are properly adjusted bear firmly against the surface of the Walls 14 of the cut.

The described arrangement of jack-arms may be applied to the machine at present in use, the result being that by increasing the length of the boom the said machine may be employed for the excavation of a cut considerably Wider than that for which the machine was originally designed.

Having thus described the invention, what is claimed as new, and desired to be protected by Letters Patent, is#

ln a machine of the character described, the combination With an A-shaped supporting-standard of a pair of jack-arms hinged to the apex portion of said standard so as to swing in a vertical plane.

In Witness whereof l have hereunto set my hand.

EGBERT B. STONE.

W'itnesses:

N. A. AGKER, D. B. RICHARDS. 

